Automatic text color fails to persist on document reload

Describe the bug
When using dark mode with a dark background, the font color initially appears black. Switching the font color to Automatic correctly changes it to white. However, after closing and reopening the document, the automatic color setting is not preserved. The font reverts to black, making the text invisible against the dark background.

To Reproduce
Steps to reproduce the behavior:

1. Open a document in dark mode with a dark background.
2. Set the font color to Automatic.
3. Close the document.
4. Reopen the same document.
5. Observe that the text color has reverted to black instead of remaining white.

Expected behavior
The Automatic font color setting should be saved and restored when reopening the document. Text should remain visible and correctly adapt to the dark background.

Client details:

• OS: W11
• Browser : Brave

Server details

Nextcloud version: 31.0.10

Version of the richdocuments app 8.7.6

Version of Collabora Online 25.04.6.2

The issue does not identify a source file, test, or entry point. Start by reproducing the Automatic font color behavior in dark mode with the reported Nextcloud, richdocuments, and Collabora Online versions, then trace how the color setting is saved and restored on document reload. Done means the setting persists and the text remains visible after reopening.